This application is the US national phase of PCT application PCT/EP99/00928 filed Feb. 12, 1999 with a claim to the priority of German patent application 19809954.1 itself filed Mar. 7, 1998.
The invention relates to a longitudinal slitter for a winding machine for winding up advancing workpiece webs, in particular plastic webs, with a row of upper blades that are formed as disk-shaped circular blades and with a row of lower blades that are formed as circular blades.
Winding machines known as roller cutting machines have as is known a longitudinal slitter that subdivides the workpiece web by longitudinally cutting it into individual strips that are subsequently wound up into rolls. It is necessary when winding up plastic webs that two adjacent rolls have a certain spacing from one another so that if a web is misfed it does not get caught. Any contact between two adjacent winding rolls at their ends must also be avoided so that in the event of profile variations there is no friction between two winding rolls when they grow radially differently.
In order that each roll has the necessary axial spacing from the neighboring roll, the rolls are as is known wound up on two parallel winding shafts that are spaced from each other. The individual webs are alternately fed to one of the two winding shafts so that adjacent rolls are wound up offset from one another. This makes the equipment relatively expensive since the winding machine needs two winding shafts.
In order to be able to wind up all the rolls on a common winding shaft with the necessary spacing rom one another it has been suggested to cut a small strip out of the web during the longitudinal slitting so as to hold two adjacent winding rolls at the necessary axial spacing from each other. This procedure, which simplifies the construction of the winding machine, is not acceptable able since the strip cut out between the two webs and discarded must be very narrow so that the waste is tolerable. In addition there is the problem during cutting of conducting the extremely narrow strip out of the longitudinal slitter.
It is therefore an object of the invention to provide a longitudinal slitter for a winding machine that allows a strip less than 5 mm wide to be cut out of the web and carried off.
This object is attained with the features of claim 1.
The dependent claims described preferred particularly advantageous embodiments of a longitudinal slitter according to the invention.